1. Technical Field
The present invention relates to a method of treating radioactive metal waste using melt decontamination, and, more particularly, to a method of treating radioactive metal waste using melt decontamination, wherein radioactive metal waste, which is generated from nuclear fuel processing facilities or nuclear fuel production facilities, which cannot be easily treated by surface decontamination because it has a complicated geometric shape, and the surface contamination of which cannot be measured, can be treated by melt decontamination.
2. Description of the Related Art
Generally, there are various types of radioactive waste generated from nuclear power plants, nuclear research institutes and the like, such as metals, concretes, contaminated oil and the like occurring when maintaining and dismantling nuclear facilities, and a large amount of this waste is generated.
Among the various types of radioactive waste, the cost for reprocessing or recycling radioactive metal waste is far lower than the cost for producing a product using new natural resources. For this reason, when radioactive metal waste is discarded and not recycled, there may be a great loss in terms of environmental protection and economic efficiency.
Radioactively-contaminated metal waste may be classified into corrosion products included in a primary cooling medium of a nuclear reactor and radiation products produced by the irradiation of neutrons during the operation of a nuclear reactor. Radioactive contaminants adhering to the surface of a metal can be removed by chemical and mechanical decontamination.
However, radiation products are problematic in that they cannot be removed just by surface decontamination because they are distributed even in the metal matrix, and in that their surface contamination cannot be measured because metal products having a complicated geometric shape, such as bolts or nuts, are difficult to treat using surface decontamination and they have a planar area smaller than the effective area of a measuring instrument.
Melt decontamination is advantageous in that the volume of radioactive metal waste is reduced, which well accords with the management target required for the final disposal of radioactive waste, and in that radioactive waste can be safely treated as well as recycled.
Meanwhile, conventional surface decontamination for treating radioactive metal waste is problematic in that metal contaminants having a complicated geometric shape cannot be removed, and in that contaminants distributed in the matrix of metal as well as on the surface of metal cannot be removed. As conventional methods of treating radioactive metal waste, Korean Patent registration No. 10-0822862 discloses a decontamination system for collectively treating radioactive metal waste and a decontamination method using the same, and Korean Unexamined Patent Publication No. 10-2008-0026577 discloses a system for treating middle and low level radioactive waste.